Lagophthalmos commonly results in exposure keratopathy and may lead to corneal ulceration, and globe perforation. While most often a result of de-innervation of the orbicularis oculi, the resulting exposure may be directly caused by upper eyelid retraction (unopposed protractors), decreased blink excursion or frequency and/or lower eyelid ectropion. Initial management is supportive consisting of the frequent use of ocular lubricants. Additional conservative options include eyelid taping, bandage contact lenses, moisture chambers, adhesive eyelid weights, botulinum toxin, and hyaluronic acid gel (De Maio M. Use of botulinum toxin in facial paralysis. J Cosmet Laser Ther 2003; 5:216-7; Mancini R, et al. Use of hyaluronic acid gel in the management of paralytic lagophthalmos: the hyaluronic acid gel “gold weight. Ophtha Plast Reconstr Surg 2009; 25(1):23-26.). Often, despite aggressive conservative therapy, the exposure keratopathy progresses and a temporary or permanent surgical alternative is sought.
Traditionally, surgical interventions for the short term include temporary medial and/or lateral tarsorrhaphies. However, this technique often requires repeated suturing secondary to eyelid inflammatory responses to the suture material. Additionally, it is not simple to temporarily reverse, thereby causing distorted eyelid anatomy in public settings and making ophthalmic examination more difficult (Mansolf F A. Techniques for the repair of orbicularis oculi palsy. Ophthalmic Surg 1978 19:67-70; Lessa S, et al Ophthal Plast Reconstr Surg 2009; 25 (3): 189-193.). Permanent lateral and medial tarsorrhaphies have similar limitations, and, in a more permanent fashion, decrease patient cosmesis.
Other surgical options reported include temporalis or masseter muscle flaps, fascia lata grafts, and direct facial or autogenous nerve grafts. Unfortunately, these techniques result in distortion of palpebral fissure anatomy, impair spontaneous blinking, require more than one surgical step, and are significantly more complex technically (Lessa et al 2009; Adams W M. The use of masseter, temporalis and frontalis muscles in the correction of facial paralysis. Plast Reconstr Surg 1946; 1:216-28. Pirello R, D'Arpa S, Moschella F. Static treatment of paralytic lagophthalmos with autogenous tissues. Aesth Plast Surg. 2007; 31:725-31; Seiff S R and Chang J S Jr. The staged management of ophthalmic complications of facial nerve palsy. Ophthal Plast Reconstr Surg 1993; 9:241-9).
There are many other techniques for upper eyelid lowering, which include müllerectomy, full-thickness blepharotomy, transcutaneous or transconjunctival levator recession and levator marginal myotomy. While these techniques can sufficiently treat patients with facial nerve palsy, they are static in nature and are limited in the amount of the corneal protection they can provide. (Seiff and Chang 1993; Hassan A S et al. Müllerectomy for upper eyelid retraction and lagophthalmos due to facial nerve palsy. Arch Ophthalmol 2005; 123:1221-5; Demirci H, et al. Graded full-thickness anterior blepharotomy for correction of upper eyelid retraction not associated with thyroid eye disease. Ophthal Plast Reconstr Surg 2007: 23:39-45; Demirci H and Frueh B. Palpebral spring in the management of lagophthalmos and exposure keratopathy secondary to facial nerve palsy. Ophthal Plast Reconstr Surg 2009: 25(4):270-5.)
Reconstruction techniques have can also involve implantation. Silicone encircling bands allow for dynamic lid closure, but have been abandoned due to difficulty in balancing band tension with levator palpebrae muscle force, along with a limited life span of about 6 months (Lessa et al 2009; Seiff and Chang 1993; Hassan et al 2005). Palpebral springs also allow for dynamic lid closure with the possibility for individualized height adjustment, but have the disadvantage of metal fatigue, dislocation, extrusion, and granuloma formation (Demirci et al 2007; Mansolf 1978).
The most frequently used technique, eyelid-loading with a metal weight, has its complications as well. Although gold is considered to be an unlikely allergen, there is still risk of allergy, in addition to extrusion, eyelid distortion, induced astigmatism, nocturnal lagophthalmos, undercorrection or overcorrection with resultant residual lagophthalmos or blepharoptosis, respectively. Furthermore, complete facial nerve recovery can occur in 21-83% patients, depending on the etiology, which can necessitate weight removal (Peitersen E. Bell's palsy: the spontaneous course of 2,500 peripheral facial nerve palsies of different etiologies. Acta Otolaryngol Suppl 2002:4-30). Platinum weights offer lower profiles and may be an option for patients with documented gold allergies (Silver A L, Lindsay R W et al. Thin profile platinum eyelid weighting: a superior option in the paralyzed eye. Plastic and Reconstr Surg. 2009; 123 (6): 1697-1703).
In 1973, Mühlbauer et al published a procedure that used magnetic implants into the upper and lower eyelid to afford closure (Mühlbauer W D, Segeth H, Viessmann A. Restoration of lid function in facial palsy with permanent magnets. Chir plastic (Berlin) 1973; 1:295.). Several years later, Riehm et al published promising data in 29 patients using this method (Riehm E, Hinzpeter E N. Experience with magnet implantation in lagophthalmos. Klin Mbl Augenheilk. 1976; 169: 524-8.).
Patients may also suffer conditions or diseases in which they cannot open their eyelids fully, a condition known as ptosis. Ptosis may be caused by damage/trauma to the muscle which raises the eyelid, damage to the superior cervical sympathetic ganglion or damage to the nerve (3rd cranial nerve (oculomotor nerve)) which controls this muscle. Such damage could be a sign or symptom of an underlying disease such as diabetes mellitus, a brain tumor, and diseases which may cause weakness in muscles or nerve damage, such as myasthenia gravis. Exposure to the toxins in some snake venoms, such as that of the black mamba, may also cause this effect. Ptosis may be due to a myogenic, neurogenic, aponeurotic, mechanical or traumatic cause and it usually occurs isolated, but may be associated with various other conditions, like immunological, degenerative, or hereditary disorders, tumors, or infections.
Ptosis may require surgical correction if severe enough to interfere with vision or if cosmesis is a concern. Treatment depends on the type of ptosis and is usually performed by an ophthalmic plastic and reconstructive surgeon, specializing in diseases and problems of the eyelid. Surgical procedures include Levator resection, Müller muscle resection, and Frontalis sling operation. Non-surgical modalities like the use of “crutch” glasses or special Scleral contact lenses to support the eyelid may also be used. Mühlbauer et al also tested their implanted double magnet systems in rabbit models of ptosis with promising results. They placed one magnet on the lower margin of the upper eyelid, and the other along the upper orbital rim firmly fixed to the periosteum. (Muehlbauer et al 1973).